Dry crumbly discharge for over a year

So about a year ago I’ve started getting dry crumbly discharge that mimics yeast infection discharge, and I don’t know why or what it could be. I can’t get wet anymore I’ve tried lube, maca root, and even birth control nothing helps. I’ve gone to three gynecologist and none of them have helped. They tested me for STDS, Yeast, and BV and I don’t have any of those things. I don’t know what it could be. I’ve also tried Boric Acid and it didn’t help. Does anyone know what could be causing this? I just want to have a normal healthy vagina again.